An air conditioner is an apparatus for maintaining air of a predetermined space in an ideal state according to usage or purposes thereof. In general, the air conditioner includes a compressor, a condenser, an expansion device and an evaporator. A freezing cycle for performing compression, condensation, expansion and evaporation of refrigerant may be performed to cool or heat the predetermined space.
The predetermined space may be changed according to where the air conditioner is used. For example, when the air conditioner is positioned in home or office, the predetermined space may be an indoor space of a house or building. In contrast, when the air conditioner is positioned in a vehicle, the predetermined space may be a space into which a person gets.
When the air conditioner performs cooling operation, an outdoor heat exchanger provided in an outdoor unit performs a condensation function and an indoor heat exchanger provided in an indoor unit performs an evaporation function. In contrast, when the air conditioner performs heating operation, the outdoor heat exchanger performs a condensation function and the indoor heat exchanger performs an evaporation function.
FIG. 1 shows the configuration of a conventional air conditioner.
Referring to FIG. 1, the air conditioner 1 includes a set temperature input unit 2 for inputting the set temperature of an indoor space, an indoor temperature sensor 3 for sensing the temperature of the indoor space and a controller 7 for controlling operation of a compressor 4, an outdoor fan 5 and an indoor fan 6 based on the temperature information sensed by the indoor temperature sensor 3 and the set temperature input unit 2.
The set temperature input unit 2, the indoor temperature sensor 3 and the indoor fan 6 may be provided in an indoor unit and the compressor 4 and the outdoor fan 5 may be provided in an outdoor unit.
For example, upon performing the cooling operation of the air conditioner 1, if the temperature value sensed by the indoor temperature sensor 3 is higher than the set temperature value input via the set temperature input unit 2, the controller 7 may operate the compressor 4, the outdoor fan 5 and the indoor fan 6. Such operation may be continuously performed until the temperature of the indoor space reaches the set temperature value.
In the conventional air conditioner, operation of the compressor and a blast fan is controlled based on the temperature value of the indoor space, but humidity is not considered in operation of the air conditioner. When humidity is relatively high, a person in the indoor space may be uncomfortable.
Capacity of the air conditioner includes sensible-heat load for decreasing an indoor temperature and potential-heat load for decreasing humidity of the indoor space. When the indoor temperature or humidity is high, the air conditioner needs to decrease an evaporation temperature in order to obtain greater cooling capacity.
However, as described above, since the conventional air conditioner does not consider humidity, the conventional air conditioner is designed such that the evaporation temperature is set to be equal to or less than the set temperature in the freezing cycle, in order to display sufficient capacity even in an environment in which humidity is relatively high, such as summer.
When the air conditioner operates in an environment in which humidity is low, operation efficiency deteriorates due to excessive compression operation and a cold draft is generated due to an excessively low discharge temperature.